Thursday, February 1, 2018

Half-blind dovetails, part 2

My test joints turned out well enough that I decided to go ahead and finish the drawer, which I will find a use for at some point.  I did find that very careful fine-tuning made a difference but some small gaps remained.  I used a filler of glue and sawdust to fill the gaps and this is what I ended up with:


Pretty good, could be better. The best way I have found to fill small gaps in dovetails is sawdust and shellac and that's what I will go back to in the future.

Here's how I think I can improve:
  1. I need to make further progress on precise, crisp marking out of the pin board but in a way that produces a line I can follow;
  2. Although I have made significant strides, there is always room for further improvement in sawing technique.  
I decided that I would try to use a marking knife but then find some way to highlight the knife line so I can see it.  After a number of unsuccessful experiments, I settled on putting a chisel in the knife line and drawing a line with a .5 mm mechanical pencil along the back of it.  Here's what it looks like under magnification:


After all of the fumbling around marking out dovetail pins that I have done, this simple and obvious solution seems like it is going to work. I think it is better than the masking tape trick or any other method I know of. Quicker too.

Here's the result:



This is dry fit off the saw and chisel and is a significant improvement. Further improvement depends on sawing accuracy, so this is what I am focused on.

I ran out of wide scraps, so I had to start making shallower drawers:


If I could make them this well on a consistent basis, I'd be satisfied.

Now I have two wide drawers and two shallow drawers and nothing to put them in.  May have to think of a project.








4 comments:

  1. That magnified photo is a FANTASTIC picture! I've been using a knife to transfer my tail outline to the pin board end grain. Then I typically pencil in the knife line. I once read something Schwarz wrote about doing it this way. He noted that the pencil line will darken both sides of the mini-canyon created by the knife line. Then he saws to remove the half the pencil line that is on the waste side. I recently did this with some success. But it was in pine, where I can easily see the pencil lines. I'm about to try it in red oak. Could be more difficult to see.

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  2. Matt,

    I tried that and was getting a slight gap. I don't know if this makes sense, but it seems like if you saw into the knife line you will be slightly cutting into the pin. In any case, I find it easier to saw to the edge of the pencil line than trying to split it. Just personal preference.

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  3. Your side board cuts look 'fuzzy' like maybe you are using pine or softwood. Try poplar, I've been practicing with dovetails in poplar a lot and it gives a nice cut with no fuzz. I've tried rubbing white chalk into knife lines in darker wood with good success. Those stress cracks bothered me for a lot of my early dovetail drawers, you can relieve the tails' wood with a chisel inside the joint where you won't see it and they will stop. Practice.

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  4. I am using scrap douglas-fir for the sides. It is fuzzy and is also prone to small splits along the corners but I would like to use it if possible. I looked at poplar at my supplier but it was a green color I didn't like.

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